1. Field of the Invention
This invention relates to a weather strip having a curved corner section. Examples of such a weather strip including an opening trim attach to an opening peripheral edge of an automobile body. The opening is open and closed with a panel such as a side door panel, a hatchback door panel, a trunk panel, a quarter window panel and a sliding roof of the automobile. The weather strip is attached to one of such opening peripheral edge and open and closed panels.
2. Description of Related Art
According to the first conventional weather strip as shown in FIG. 23, an opening trim (weather strip) 51 is attached to a flange 2 of an opening peripheral edge of an automobile body 1, which seals a gap between the body 1 and a door panel 3 when the door panel 3 is closed. The opening trim 51 is mainly composed of an extruded product 52, as shown in FIGS. 24 and 25. The extruded product 52 is formed by common extrusion from a solid rubber, which forms an attachment portion 53 and a lip portion 55, and a sponge rubber, which forms a hollow (loop-shaped) sealing portion 54. The attachment portion 53 has a metal reinforcing insert 56 embedded therein. The sealing portion 54 is connected to the attachment portion 53 at both ends of the loop.
Since the opening trim 51 is required to be curved along a corner of the door opening peripheral edge, it has a corner section C which curves between straight sections S, S. In order to form the corner section C where this curved shape is maintained, the sealing portion 54 in the corner section C is first cut off remaining its inner peripheral part 54a, as shown in FIG. 24. Next, the extruded product 52 is set in a molding apparatus (not shown) with being curved at the corner section C, and a sponge rubber material is injected into the cut off part of the sealing portion 54, thereby forming a molded part 57, as shown in FIG. 25. At this time, the molded part 57 is connected to the remaining inner peripheral part 54a. In order to expand the sealing area of the corner section C toward its outer periphery according to the corner shape of the door panel 3, the molded part 57 is formed so as to project toward the outer periphery of the corner section C. In FIG. 25, cross-hatching lines are shown only to make the range of the molded part 57 clear.
However, since the sealing portion 54 in the corner section C is almost cut off and replaced by the molded part 57, the range of the molded part 57 becomes large, which brings a problem in the appearance and durability of the resulting opening trim 51.
Namely, even if the same kind of sponge rubber material is used for the sealing portion 54 of the extruded product 52 and the sealing portion of the molded part 57, they are different from each other in luster on their surfaces due to the difference in their forming method and a slight difference in their material and expansion ratio, and a borderline 58 is seen between them, which impairs the appearance of the corner section C. Furthermore, since the sealing portion 54 of the extruded product 52 and the sealing portion of the molded part 57 are different from each other in their state of deterioration, which is brought by the contact with the door panel 3, their difference in luster on their surfaces becomes greater with the passage of time.
In addition, the molded part 57 is formed from a molding material whose composition shows a good fluidity in a cavity, so the sealing portion of the resulting molded part 57 is rather soft. As a result, there also is a problem that the sealing portion of the molded part 57 is inferior to the sealing portion 54 of the extruded product 52 in the durability.
According to the second conventional weather strip as shown in FIGS. 30 to 32, an opening trim 151 is attached to a flange 102 of an opening peripheral edge of an automobile body 101, which seals a gap between the body 101 and a door panel 103 when the door panel 103 is closed. The opening trim 151 is mainly composed of an extruded rubber product 152 except for a molded part. The extruded rubber product 152 is formed by common extrusion from a solid rubber, which forms an attachment portion 153 and a lip portion 155, and a sponge rubber, which forms a hollow sealing portion 154. The attachment portion 153 has a metal reinforcing insert 156 having a U-shaped cross-section. The attachment portion 153 has a cover layer 161 for surface decoration, which extends from the boundary with the sealing portion 154 of the attachment portion 153 to the back side of the lip portion 155 via its tip edge. The cover layer 161 may be a cloth, a synthetic resin seat or a molded material from a coloring resin.
At a corner section 152a of the extruded rubber product 152, a molded part 157, which has a curved configuration and has a projecting part extending toward the outer peripheral side over the outer peripheral outline of the attachment portion 153 in accordance with the corner shape of the door panel 103, is provided. In order to form the molded part 157, the sealing portion 154 in the corner section 152a is first cut off remaining its inner and outer peripheral parts 154a and 154b. These parts 154a and 154b form inner and outer peripheries of the extruded rubber product 152 when the product 152 is curved, respectively. Next, the extruded rubber product 152 is set in a metal mold with being curved to accord with the corner shape of the door panel 103, and a sponge rubber is injected into the cut off part of the sealing portion 154, thereby forming a molded part 157.
However, once the extruded rubber product 152 is removed from the mold after the molded part 157 is formed as shown in FIG. 33, the corner section 152a, which has been curved until then, almost recovers its straight shape by the shape recovery force of the insert 156 as shown in FIG. 34. This requires operators who assembles the opening trim 151 onto an automobile body to curve the corner section 152a again with their hands so as it to accord with the corner shape of the door panel 103, which is bothersome.
Moreover, when the corner section 152a recovers its straight shape, hems 157a on the both sides of the projecting part of the molded part 157 are loosened, thereby transforming the projecting part into wavy shape. If a long period of time passes with the projecting part being transformed into wavy shape, the wavy shape remains in the projecting part, which deteriorates a sealing ability and appearance of the projecting part.
Furthermore, since the molded part 157 is formed from a sponge rubber, a heated metal mold is used to vulcanize the rubber. To prevent the heat from the heated metal mold from melting the surface of the cover layer 161, the remaining inner peripheral part. 154a of the sealing portion 154, which is connected with the molded part 157, is required to be large so as to be used as a heat insulator for preventing heat transfer from the heated metal mold to the surface of the cover layer 161. For this purpose, the boundary where the inner peripheral part 154a connects with the molded part 157 is easily seen from outside, which impairs the appearance.
Furthermore, since the projecting part of the molded part 157 ends in a free edge, it is easy to be turned over or swayed by the open and closed of the door panel or its aged deterioration, which deteriorates a sealing ability and appearance of the projecting part.
It is, therefore, an object of this invention to provide a weather strip which can provide an uniform luster on its surface by making an extruded sealing portion to appear on its surface as much as possible even in a corner section and which can hardly make a borderline between an extruded part and a molded part to see, thereby improving the appearance. Furthermore, it is another object of this invention to provide a weather strip which can improve the durability of a sealing portion in a corner section.
It is further object of this invention to provide a weather strip which can improve an assembling ability onto an automobile body, a sealing ability and an appearance by preventing a shape recovery of a curved corner section.
At first, the following measures are taken to attain the above objects.
The first invention provides a weather strip comprising an extruded body having straight sections and a corner section curving therebetween, the extruded body comprising an attachment portion and a hollow sealing portion integrally formed by an extrusion molding, the attachment portion being attached to a part of an automobile and the sealing portion being connected to the attachment portion at both ends, wherein the weather strip comprises: an incision slit made on the outer periphery of the sealing portion in the corner section; an incision edge formed on the sealing portion along the incision slit, the incision edge being spread out toward the outer periphery of the corner section with the attachment portion and sealing portion being curved along a corner shape of the part of the automobile; and a molded part formed at least in the vicinity of the incision edge on the back side of the sealing portion in the corner section.
The second invention provides a weather strip comprising an extruded body having straight sections and a corner section curving therebetween, the extruded body comprising an attachment portion and a hollow sealing portion integrally formed by an extrusion molding, the attachment portion being attached to a part of an automobile and the sealing portion being connected to the attachment portion at both ends, wherein the weather strip comprises: a cutout long hole made by cutting out at least a part of the sealing portion which is on the outer periphery of the corner section and not seen from the front side; a cutout edge formed on the sealing portion along the cutout long hole, the attachment portion and sealing portion being curved along a corner shape of the part of the automobile; and a molded part formed at least in the vicinity of the cutout edge on the back side of the sealing portion in the corner section and in a place which projects from the cutout edge toward the outer periphery of the corner section.
The third invention provides a weather strip comprising an extruded body having straight sections and a corner section curving therebetween, the extruded body comprising an attachment portion and a lip-shaped sealing portion integrally formed by an extrusion molding, the attachment portion being attached to a part of an automobile and the sealing portion being connected to the attachment portion at one end with the other end thereof being free, wherein the weather strip comprises: a free edge formed by locating the other end of the sealing portion on the outer periphery of the corner section; at least one cut made in the sealing portion from the free edge toward the inner periphery of the corner section, the free edge being spread out toward the outer periphery of the corner section with the attachment portion and sealing portion being curved along a corner shape of the part of the automobile; and a molded part formed at least in the vicinity of the fee edge on the back side of the sealing portion in the corner section and inside the cut which is expanded by the curved transformation of the sealing portion.
A weather strip according to each of the above described inventions can provide an uniform luster on its surface by making an extruded sealing portion to appear on its surface as much as possible even in a corner section. The weather strip can hardly make a borderline between an extruded part and a molded part to see, thereby improving the appearance. Furthermore, the durability of a sealing portion in a corner section can also be improved.
The incision slit or cutout long hole may be provided within the range of the corner section, or it may reach the straight sections over the corner section.
It is preferable that at least one cut is made in the sealing portion from the incision edge or cutout edge toward the inner periphery of the corner section, and that the molded part is further formed inside the cut which is expanded by the curved transformation of the sealing portion.
The cut may be made in the sealing portion in the vicinity of each boundary between the corner section and the straight sections, or it may be made in the sealing portion in the middle of the corner section.
It is preferable that each end of the incision slit or cutout long hole undergoes a rounding finish. It is also preferable that the end of the cut undergoes a rounding finish. This is because stress concentration in each end can be improved by such a finish. For example, a round hole may be formed at an end of a cut or an incision slit. Each end of a cutout long hole may form a semicircle.
In a manner, the molded part is not formed over to project from the spread incision edge or free edge toward the outer periphery of the corner section. In another manner, the molded part is further formed in a place which projects from the spread incision edge or free edge toward the outer periphery of the corner section.
The former manner is suitably employed when spreading out the incision edge or free edge is sufficient to expand the sealing area of the corner section toward its outer periphery, and it has the advantage of being able to hardly show the molded part. The latter manner is suitably employed when spreading out the incision edge or free edge is insufficient to expand the sealing area of the corner section toward its outer periphery. Although a little of the molded part projecting from the incision edge or free edge can be seen from outside according to the latter manner, the majority which can be seen from outside besides the slight molded part is the extruded sealing portion, so that the appearance of the resulting weather strip is hardly impaired. Likewise, although a little of the molded part projecting from the cutout edge can be seen from outside according to the second invention, the majority which can be seen from outside besides the slight molded part is the extruded sealing portion, so that the appearance of the resulting weather strip is hardly impaired.
Moreover, in each manner, the molded part may be formed on the entire back side of the sealing portion in the corner section, or it may be formed only in the vicinity of the incision edge, free edge or cutout edge on the back side of the sealing portion in the corner section.
It is preferable that at least one rib is integrally formed on the back side of the molded part, extending in the direction where the corner section curves along. This is because the rib reinforces the rigidity of the molded part, and serves to maintain the curved shape of the corner section.
The molded part is not limited by its molding method such as a casting, an injection molding and a transfer molding. Examples of the flowing direction of a molding material for the molded part include the following manners (a) and (b):
(a) A manner wherein the molded part is formed by injecting a molding material into a region in the vicinity of the outer surface of the attachment portion which faces the back side of the incision edge, free edge or cutout edge in the center of the corner section so as it to flow along the back side of the sealing portion from the inner periphery toward the outer periphery of the corner section; and
(b) A manner wherein the molded part is formed by injecting a molding material into a region in the vicinity of the back side of the incision edge, free edge or cutout edge in the center of the corner section so as it to flow along the back side of the sealing portion from the outer periphery toward the inner periphery of the corner section.
In each of manners (a) and (b), it is possible to set the molding material to reach final positions on the outer periphery of the corner section in the vicinity of each boundary between the corner section and straight sections. It is also possible to provide a tab on the outer periphery of each final position so as to prevent the air from remaining.
Although the attachment portion and sealing portion of the extruded body are preferably formed from a rubber, a thermoplastic elastomer also may be used. The molded part may be formed from a rubber or a thermoplastic elastomer.
The forth invention provides a weather strip comprising an extruded body having straight sections and a corner section curving therebetween, the extruded body comprising an attachment portion and a sealing portion integrally formed by an extrusion molding, the attachment portion being attached to a part of an automobile, the sealing portion sealing a gap between an opening peripheral edge of the automobile and an open and closed panel, the sealing portion being cut off in a curved corner section, and a curved molded part being formed in place of the cut off part, wherein the molded part is formed from a soft thermoplastic elastomer (TPE), and a recovery preventing portion is formed on the attachment portion by an injection molding from a hard resin, the recovery preventing portion extending in the peripheral direction of the corner section.
A weather strip according to the forth invention can improve an assembling ability onto an automobile, a sealing ability and an appearance by preventing a shape recovery of a curved corner section.
It is preferable that the molded part comprises a projecting part extending toward the outer peripheral side over the outer peripheral outline of the attachment portion, and a belt-shaped bridge connecting the outer edge of the projecting part and the attachment portion. Such a construction prevents the projecting part of the molded part from turning over or swaying by the open and closed of the door panel or its aged deterioration, thereby improving the sealing ability and appearance.
Although the region on the attachment portion where the recovery preventing portion is formed is not specifically limited, it is effective in preventing recovery to form the recovery preventing portion to have a width parallel to a sidewall of the attachment portion. For instance, if the attachment portion has a U-shaped cross-section, it is possible to form the recovery preventing portion on the inner surface or outer surface (including a surface which is appeared outside by the cut off of the sealing portion) of the U shape.
Further objects of this invention will become evident upon an understanding of the illustrative embodiments described below. Various advantages not specifically referred to herein but within the scope of the instant invention will occur to one skilled in the art upon practice of the presently disclosed invention. The following examples and embodiments are illustrative and not seen to limit the scope of the invention.